Methods: A retrospective computed tomography (CT)-based analysis of the endplate cavities and fusion status following PLIFs with PEEK cages was conducted by two independent observers. The term “cavity” was used to describe the endplate changes. The vertebral endplate cavities were assessed according to the size, multiplicity, location, and presence or absence of sclerosis. Results: There were 86 fixed levels in 65 consecutive patients, with a mean age of 35.44±19.60 years. The mean follow-up was 16.5±10.1 months (range, 6–57 months). Definite fusion was seen in 56 levels (65.12%) by observer 1 versus 44 levels (51.16) by observer 2. The strength of agreement was moderate. Endplate cavities were observed in 42 levels (48.84%) by observer 1 versus 47 levels (54.65%) by observer 2, with fair agreement. The strengths of agreement for the locations, multiplicity, and size were moderate, fair, and poor, respectively. Neither age, sex, etiology, levels, nor follow-up period was significantly associated with the presence of cavities. With regard to fusions, the nonunions detected by observer 1 were significantly associated with the presence of cavities (p<0.0001). However, those detected by observer 2 were nearly significant (p=0.05). Conclusions There was a high rate of unfavorable radiographic findings in the form of endplate cavities in PLIF cases with PEEK cages. A more comprehensive classification for the assessment of fusions and endplate cavities should be formulated. We strongly recommend further CT-based studies with larger sample size and longer follow-up periods.

PURPOSE: To investigate and compare the surface roughness (SR), weight and height of monolithic zirconia (MZ), ceramometal (CM), lithium disilicate glass ceramic (LD), composite resin (CR), and their antagonistic human teeth enamel. MATERIALS AND METHODS: 32 disc shaped specimens for the four test materials (n=8) and 32 premolars were prepared and randomly divided. SR, weight and height of the materials and the antagonist enamel were recorded before and after subjecting the specimens to 240,000 wear-cycles (49 N/0.8 Hz/5℃/50℃). SR, height, weight, and digital microscopic qualitative evaluation were measured. RESULTS: CM (0.23 + 0.08 µm) and LD (0.68 + 0.16 µm) exhibited the least and highest mean difference in the SR, respectively. ANOVA revealed significance (P=.001) between the materials for the SR. Paired T-Test showed significance (P < .05) for the pre- and post-SR for all the materials. For the antagonistic enamel, no significance (P=.987) was found between the groups. However, the pre- and post-SR values of all the enamel groups were significant (P < .05). Wear cycles had significant effect on enamel weight loss against all the materials (P < .05). CR and MZ showed the lowest and highest height loss of 0.14 mm and 0.46 mm, respectively. CONCLUSION: MZ and CM are more resistant to SR against the enamel than LD and CR. Enamel worn against test materials showed similar SR. Significant variations in SR values for the tested materials (MZ, LD, CM, and CR) against the enamel were found. Wear simulation significantly affected the enamel weight loss against all the materials, and enamel antagonist against MZ and CM showed more height loss.
Bicuspid ; Ceramics ; Dental Enamel ; Evaluation Studies as Topic ; Glass ; Humans ; Lithium ; Tooth ; Tooth Wear ; Weight Loss

STUDY DESIGN: Retrospective study. PURPOSE: The study aims to assess the effectiveness and safety of radiofrequency (RF) kyphoplasty in the treatment of vertebral compression fractures (VCFs) in osteoporotic patients. OVERVIEW OF LITERATURE: Vertebroplasty and balloon kyphoplasty are established procedures for the treatment of osteoporotic VCFs. However, RF kyphoplasty is a new method which controls cement viscosity. METHODS: We reviewed the results of 41 consecutive patients with 23 thoracic and 38 lumbar VCFs who underwent RF kyphoplasty. The study population included 14 males (34%) and 27 females (66%). The mean patients age was 78 years (range, 51–89 years), and the follow-up period was 1 year. Clinical and radiographic analyses were performed during follow-up at 6 weeks, 6 months, and 1 year. All patients were assessed clinically pre- and postoperative using the Visual Analog Scale (VAS) and Oswestry Disability Index (ODI). Radiological assessment with X-ray in two views preoperatively, postoperatively, and during follow-up visits. RESULTS: The mean preoperative VAS was 8.7 (range, 5–10; standard deviation [SD], 1.2). Postoperatively, VAS decreased by 3.3 (range, 2–5; SD, 0.9). At the end of the follow-up, VAS decreased by 1.22 (range, 0–7; SD, 1.6). The mean preoperative ODI score was 85.9, decreasing to 9.6 postoperatively and improving to 18.4 during the 1-year follow-up. The mean local kyphotic angle was 9.04° before the procedure and decreased by a mean of 6.16° after the operation and at the end of the follow-up. The mean increase in vertebral body height was 3.3 mm postoperatively and after 1-year follow-up. The rate of cement leakage was 8% (five out of 61 levels of fracture). CONCLUSIONS: RF kyphoplasty is a safe and effective augmentation technique with an advantage of controlling the cement viscosity to minimize the risk of cement leakage. It also shortens operation time.
Body Height ; Female ; Follow-Up Studies ; Fractures, Compression ; Humans ; Kyphoplasty ; Male ; Methods ; Osteoporosis ; Retrospective Studies ; Vertebroplasty ; Viscosity ; Visual Analog Scale